Field of the Invention
This invention relates to an industrial truck, in particular a lift truck, with a drive section and a load section that can be raised and lowered relative to the drive section. The load section has at least one wheelarm which is provided with at least one load roller. The load roller is mounted so that it can rotate in a load roller carrier and the load roller carrier is swively-mounted by a swivel bearing on the wheelarm.
Description of Related Art
Industrial trucks with wheelarms are used to lift a pallet by driving the wheelarms under the pallet and then lifting the wheelarms to lift the pallet. For this purpose, the load section is raised or lowered relative to the drive section. Load roller carriers in which the load rollers are mounted are actuated by a system of levers and a linkage and can thus be swiveled outwardly and downwardly or inwardly and upwardly to raise or lower the wheelarms, respectively. On low-lift trucks or order pickers, a lifting movement of this type is called a low-lift, while on high-lift trucks with an additional lifting frame, it is called the initial lift.
Lift trucks with load rollers located on the wheelarms in pivoting load roller carriers, which are actuated by means of a linkage and a system of levers, are described, for example, in EP 1 690 823 B1 or DE 10 2009 033 709 A1. Conventional lift trucks are designed for the handling of standardized “euro pallets”, which have an entry height for the wheelarms of 100 mm and, for this purpose, the trucks have a wheelarm height of the wheelarms in the fully lowered position of approximately 85 mm.
With the wheelarms in the lowered position, the wheel arms can be inserted into the pickup openings of a pallet on the ground or floor. On pallets, in particular special pallets with a lower entry height of the pickup openings than on standard euro pallets, the upper sides of the wheelarms can slide along the underside of the pallet. The upper sides of the wheelarms form the load-bearing surface with which the pallet is picked up and lifted. Thus, when the wheelarms are inserted, a great deal of friction occurs under the pallet and, therefore, a great deal of force is required to push the wheelarms into the pallet. Under some conditions, the pallet can be damaged. Damage can occur in particular if the pallet is sagging under a load or is damaged, and thus the entry height of the pickup openings of the pallet, which is the distance from the surface of the road to the underside of a load bearing surface of the pallet, is reduced.
Therefore, it is an object of the invention to provide an industrial truck of the general type described above but which can be driven safely and with a small amount of force under pallets which have a low entry height.